<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>盒子模型演示</title>
    <style>
        .wai{
            border: 2px solid fuchsia;
            width: 200px;
            height: 200px;
            margin-top: 200px;
            margin-left: 600px;
        }
        .nei{
            border: 2px solid darkgreen;
            width: 100px;
            height: 100px;
            margin-top: 50px;
            margin-left: 50px;
        }
    </style>
</head>
<body>
<div class="wai">
    <div class="nei">

    </div>
</div>
</body>
</html>